This invention relates to apparatus for transferring dry bulk material from a storage facility to a mobile transport vehicle such as a truck or railway car.
The use of screw conveyors for moving loose bulk material is well known. For instance U.S. Pat. No. 6,296,106 issued Oct. 2, 2001 to V. Marchesini for a Screw Conveyor For Loose Material discloses an upright screw conveyor having a pivotable lower housing part rigidly cross connected to a housing of a transversely positioned screw conveyor. Thus the lower screw conveyor is pivotable about the axis of the upright screw conveyor.
U.S. Pat. No. 4,781,513 issued Nov. 1, 1988 to L. ajogren et al for Apparatus For Unloading Bulk Material discloses a first hydraulic motor driven screw conveyor pivotally connected at one of its ends to the rear of a dump truck bed so that is can be swung to either side of the truck by a hydraulic motor. The free end of the first conveyor discharges into a hooper of a second screw conveyor driven by a hydraulic motor. The second screw conveyor is pivotally connected on an upright axis to the first screw conveyor. The disclosed conveyor system is particularly adapted for unloading asphalt material and spreading the material in the unloading process.
When unloading dry bulk material from a stationary storage facility, the unloading apparatus, such as a chute, must be aligned with the receiving opening of the truck or railway car to which the material is transferred. It is often necessary to adjust the position of the railway car or truck in order to obtain proper alignment or registration. The before mentioned registration procedure typically requires the presence of two or more people and is time consuming. This invention provides a positionable screw conveyor arm which does not require precise positioning of the vehicle receiving the bulk material.
It is an object of this invention to provide a screw conveyor arm for unloading bulk material from an elevated storage facility to a transport vehicle, such as a truck or railway car, which can be positioned and operated by a single person.
It is a further object of the invention to provide a screw conveyor arm for unloading bulk material which does not require precise positioning of the vehicle receiving the bulk material. Another object of the invention is to provide a bulk unloading control system by which a single person controls the position of the screw conveyor apparatus for proper discharge alignment with the receiving vehicle and also controls the discharge of the bulk material.
A bulk material unloading apparatus is provided which includes an upper horizontally disposed screw conveyor having its receiving end pivotally connected on a vertical axis to a discharge structure of a storage facility and a lower horizontally disposed screw conveyor which has its receiving end pivotally connected to the underside of the discharge end of the upper screw conveyor. Bulk material is discharged into a transport vehicle through a discharge chute on the discharge end of the lower screw conveyor after the person controlling the unloading operation positions the discharge chute over the material receiving opening of the transport vehicle. Reversible electric motors power gearing to rotate the first screw conveyor relative to the storage facility and the lower screw conveyor relative to the first screw conveyor. The auger of each screw conveyor is driven by a separate electric motor. The electric motors are controlled by the unloading person through use of a hand held controller which permits the unloading person to move to a position in which he can observe the registration of the conveyor discharge chute with the bulk material receiving opening of the transport vehicle.